Regulation of dynamo-electric machines



7 REGULATION OF DYNAMO ELECTRIC MACHINES.

No. 431,216. Patented July 1,1890.

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WVILLIAM STANLEY, JR, OF GREAT BARRINGTON, MASSACHUSETTS.

REG U LATION 0F DYNAMO-ELECTRIC MACHIN ES.

SPECIFICATION forming part of Letters Patent No. 431,216, dated July 1,1890.

Application filed July 29, 1889. Serial No. 319,019. (No model.)

To all whom it may concern:

Be it known that I, VVILLIAM' STANLEY, Jr., a citizen of the UnitedStates, residing in Great Barringtomin the county of Berkshire and Stateof Massachusetts, have invented a new and Improved Method of Regulationfor Dynamo-Electric Machines, (Case No. 131,) of which the following isa specification.

The object of the invention is to automatically vary the potential ofthe current supplied to the field-magnet coils of a dynamoelectricmachine in sympathy with variations in the current required to operatetranslating devices in a work-circuit supplied with current by themachine, so as to maintain a constant, rising, or required difference ofpotential between the terminals of the workcircuit. Such variation Iprimarily accomplish by increasing or decreasing, as the case may be,the number of effective lines of magnetic force threading certain of thearmaturecoils.

In carrying the invention into effect the armature of a dynamo-electricmachine is wound with two coils or sets of coils, one of which suppliescurrent to a work-circuit, while the current developed in the other coilor set of coils is redirected and used to excite the field-magnets ofthe machine. The armature is so constructed as to afford a path for thepassage of a portion of the lines of force of the field outside of thearmature-coils which supply currents to the field-magnet coil, so thatthese coils are normally affected by only a portion of the field offorce. The relative position of the two sets of coils upon thearmature-core are such that when .a given exciting-coil is in a positionof zero electro-motive force a corresponding coil of the other set,which supplies current to the work-circuit, is at or near the positionin which maximum potential is induced in it. One or more turns of Wireconnected in series with the latter coil "are wound adjacent to andparallel with the given exciting-coil. The terminals of theexciting-coil are connected to a commutator in order to supply currentconstant in direction for the proper excitation of the field-magnets,while the terminals of those coils which supply current to thework-circuit are connected to collector-rings or to commutator-plates inthe usual manner.

The invention will be best understood by reference to the accompanyingdrawing, which is a diagram illustrating a cross-section of a dynamoconstructed to operate in accordance with the invention.

Referring to the figure, N S represent the field-lilagnets of a dynamohaving field-magnet coils m m.

C is the armature-core, upon which are wound separate coils A and B. Thecoils A and B are wound at approximately right angles to one another, sothat while one is in its position of zero elect-ro-motive force theother is at or near that position of maximum induced electro-motiveforce. The armature-coil B is wound in a recess 1), formed in the core0, into which the wires are introduced through an opening 0. After thewires are introduced into the recess 1) the opening 0 is closed by aplug or strip of iron a, secured in the opening. Thus a closed magneticcircuit is formed, giving passage to a portion of the lines of the fieldof force outside of the coil B. Parallel with the coil B and containedin the recess 1) with it is wound a coil consisting of a few turns ofwire a, connected in series with the coil A. The coil A is connectedwith the mains L L of the work-circuit WV by means of collector-rings c0, while the terminals of the coil B are conn'ected with thefield-magnet coils m m by means of a commutator D and brushes (1 (1 Itis evident that as current flows in the coil a a field of force will beset up around the wire, which will tend to change the direction of theadjacent lines of magnetic force in the field of the machine, and anincrease of current in the coil a will cause a greater or less numberoflines of force to thread the coil B when in its position of zeroelectromotive force, according to the direction in which current isflowing in the wire a.

l Vhen translating devices are connected in parallel in thework-circuit, an increase in the number of translating devices incircuit causes a decrease in the diiferenoe of potential between theterminals of the coil A supplying current to the work-circuit, and inorder to keep the difference of potential constant an increasedexcitation of the fieldmagnets is necessary. The fall in potential is,however, accompanied by an increased flow of current and more currentflows through the coil a. The coil a is so connected that the magneticfield due to the fiow of current through it tends to drive inward thelines of force passing through the armature-core exterior to the coil B;hence upon an increase of current in the coil a a greater number oflines of force will thread the coil B, thus i11- creasing the potentialdeveloped in it as it rotates, and consequently increasing theexcitation of the field-magnets and the difference of potential betweenthe terminals of the coil A. Conversely, upon a decrease in the fiow ofcurrent in the coil a more of the lines of force of the field will passthrough the armature-core exterior to the coil B, and the potential uponthe coil will diminish with acorresponding diminution in the excitationof the field-magnets. If it is desired to produce the oppositeeffectsthat is, to cause a decrease in the field strength upon anincrease in the iiow of current in the work-circuit-as, for example,when it is desired to maintain a constant current upon thework-circuitthe connections of the wire a should be reversed, so thatthe lines of the magnetic field set up by the current fiowing through itwill act in a direction to drive the lines of the field of force of themachine outward, thus decreasing the number of lines of force includedin the coil 13 upon an increase in the flow of current in the wire a,and consequently decreasing the excitation of the field-magnets.

' It is evident that with each reversal of current in the coil a theposition of the coil itself will be reversed, and thus the lines offorce developed by the current flowing in the coil a will maintain aconstant direction as related to the direction of the lines of force ofthe magnetic field of the machine.

For convenience of illustration I have shown the machine as constructedwith only two armature-coils, the one supplying current to thework-circuit and the other to the fieldmagnet coils. I11 practice,however, it is desirable, for reasons well understood by those skilledin the art, that there should be two or more armature-coils in each set,the regulating-coils being arranged with reference to thefield-supplying and work-supplying coils in the manner already shown.

\Vhile my invention is applicable to those dynamos which supply otherthan alternating currents for the operation of translating devices inthe work-circuit, its especial advantage lies in the fact that by meansof it a constant difference of potential or constant current value maybe automatically maintained between the terminals of analternate-current dynamo through great variations in the amount of loadupon the workcircuit.

I have not attempted to describe herein all possible means of carryingmy invention into effect, but only the best form of apparatus for thepurpose now known to me, various modifications of which will readilyoccur to those skilled in the art; nor doI claim herein the particularform of apparatus herein described, as I have made it the subject ofanother application for Letters Patent.

'What I do claim as new, and desire to secure by Letters Patent, is

1. The hereinbefore-dcscribed method of generating and regulatingelectric currents, which consists in generating currents in a set ofarmature-coils and maintaining a field of force thereby, causing aportion of the lines of force constituting such field to pass on tsideof such coils and controlling the number of the lines of force passingoutside of such coils by means of currentdeveloped in ,a second set ofarmaturecoils lying within such field.

2. The hereinbefore-described method of generating and regulatingelectric currents, which consists in generating currents in a set ofarmature-coils and maintaining afield of force thereby, causing aportion of the lines of force constituting such field to traverse thearmature at points where they willhave little or no inductive effectupon such coils, and controlling the number of such ineffective lines offorce by means of alternating currents flowingin a second set of coilsupon the armature.

3. The l1016l1lllGfOlO-(lOSCllIJCCI method of generating and regulatingelectric currents, which consists in generatingcurrents in a set ofarmature-coils and maintaining a field of force thereby, causing aportion of the lines of force of the field to traverse the armature atpoints where they will have little or no inductive effect upon suchcoils, and by means of alternating currents flowing in. a second set ofcoils upon such armature diverting a portion of such ineffective linesof force into positions of inductive effect upon said firstmentionedcoils.

In testimony whereofI have hereunto subscribed my name this 18th day ofJune, A.D. 1889.

XVILLIAH STANLEY, JR.

Witnesses.

SANDS F. RANDALL, D. IvEs MACKIE.

IIO

